twisting off grade 8 bolts

[chief613]

i did get the studs out relatively easy with an easy out. BUT when i took the over torque bolts out this mornin 2 of the holes spauld. After cleaning with brake cleaner and a match , one of the knives went good and i think i may have damaged the other, the 2 spauld holes didnt torque . I did retap with the same thread to clean out the stripped thread wire from the old bolts. i dont think i wanna use it not feeling confident with that knife stayin put. guess no education is free

ps i did check the torque spec and it does say 165 ftlbs

 

[RickB]

If Wallenstein specifies 165ft/lb for a 1/2"-20 grade 8 bolt and you damaged your chipper knives applying that torque to those bolts, Wallenstein owes you a new set of knives.

 

[Furu]

Are the knives threaded or is the flywheel/rotor threaded or is it bolt and nut connection between holding knife to rotor.

 

[Willl]

What model number is your Wallenstein ?

 

[chief613]

the knives are threaded
bx60

 

[Soundguy]

If Wallenstein specifies 165ft/lb for a 1/2"-20 grade 8 bolt and you damaged your chipper knives applying that torque to those bolts, Wallenstein owes you a new set of knives.

yeh, if that is in the manual.. sure sounds like a typo... should be 5/8 for that level...

 

[Luremaker]

I have a few Wallenstein attachments and here is a copy of the torque specs page from one of them. I assume they use this same page in all their manuals.

 

[Soundguy]

you weren't reading newton meters were you?

 

[not2old]

It sounds like the bolts were over-torqued, but if by chance anyone finds counterfit grade eight bolts anywhere, it should be reported to the authorities as it's an accident waiting to happen. Sooner or later someone will get seriously hurt or die.

 

[Furu]

This thread has kept me interested so when I got back I searched for a BX60 manual online.
Never found it but did find a BX62 manual and parts manual. The BX62 IPL calls for a 1/2NFx7/8" Gr 8 where the OP says it is a 1/2 NFx1" Gr 8 for the BX 60.
The BX62 manual states 165 ft lbs for 9/16" bolts but 115 ft lbs for 1/2 " bolts. (Grade 8)
Is the BX62 newer or older than the BX60?

 

[Soundguy]

you can hit standard SAE torque chatrs and see that the 160+ # number he is using is over rated for that size fastener.. reguardless of what the bx manual says. the strength of the fastener at that diameter is simply not present..

 

[Furu]

you can hit standard SAE torque chatrs and see that the 160+ # number he is using is over rated for that size fastener.. reguardless of what the bx manual says. the strength of the fastener at that diameter is simply not present..

That was why I did the "manuals" search to see how it was presented. At least for the BX62 it is presented as a standard chart not a specific value for that bolt application. Thus my 115 ft lbs for 1/2" and 165 for 9/16".The bx62 IPL was the only reference to the 1/2"NF bolt but no torque value just the generic chart. But that was the BX62 not 60.

 

[Soundguy]

i have a ford mower manual that also just provides a bolt torque chart giving sae values in the back.. not specific bolts.. etc.

 

[BukitCase]

Chief, could you have possibly skipped down a line? Take a look at the posted charts, see the torque value for a 9/16 NF grade 8? Looks kinda suspicious to me... Steve

 

[bigtiller]

Chief, could you have possibly skipped down a line? Take a look at the posted charts, see the torque value for a 9/16 NF grade 8? Looks kinda suspicious to me... Steve

That is what I am thinking also after looking at the chart. His finger didn't move straight across, it skipped down a line.

 

[Don87]

Maybe it's the dreaded.......crooked eyes syndrome

I suffer from that, as well as CRS(can't remember sh*t):laughing:

 

[Soundguy]

yep.. I'm thinking he's looking at wrong fastener size too!

 

[daugen]

Whenever I go into TSC, which is a bit of a drive for me, I always stock up on their Grade 5 and 8 bolts/nuts, etc. Seems about half the price as other places, but the hardware looks really nice. Never knew some of this was not kosher. Nor did I know not to reuse a heavily tightened bolt. Learned something very helpful here. I guess I'd better use my nice torque wrench more often that gathers dust in the tool box...
It seems most dealers use air wrenches and just let them run. Ever try to get a blade bolt off after a dealer put it on? My Dewalt electric impact gun is rated for 350 pounds, and sometimes I'm not sure the bolt will come off. Utterly impossible to do by hand. Of course, on the flip side, I recently got my Case IH back from the dealer who did some steering work and had to remove the tires, and two of the four left front wheel nuts went MIA. Glad I saw that in time. I put the new ones on, and yes, the dealer was quite happy to give me a couple of free nuts. And the mechanic I'm sure got a serious chewing out.

I may buy the occasional special from Harbor Freight, but sure never buy bolts and nuts there. Not exactly the right place to buy "mission critical" parts, and I can't imagine too many parts being more quality important than a chipper blade bolt.

 

[Soundguy]

yes.. some places are bad about using impacts and no TW's


as for the 350# electric.. i'm not surprised it has a hard time taking anything off. nothing personal.. it's just a bit anemic for tractor work IMHO.

 

[Gale Hawkins]

yes.. some places are bad about using impacts and no TW's


as for the 350# electric.. i'm not surprised it has a hard time taking anything off. nothing personal.. it's just a bit anemic for tractor work IMHO.

Our 450 FP Ridgid sometimes needs some help from PB Blaster I know.

R6300 HD Impact Wrench - RIDGID Professional Tools

We carry it in the MH to remove/reinstall wheels is the reason we went electric. The nuts only torque at 175 FP on our P30 chassis.